Current treatment for hepatitis C (HCV) genotype 1, the most common subtype, is a combination of two drugs, pegylated interferon and ribavirin, given over 48 weeks. This treatment cures less than half of patients and has side effects that make it difficult for some patients to complete the treatment, researchers say. Both reports are published in the April 30 issue of the New England Journal of Medicine.

"Hepatitis C is curable," said the lead researcher of the first study Dr. Jean-Michel Pawlotsky, from the Henri Mondor Hospital, University of Paris, in France. "Currently, 40 to 50 percent of patients infected with HCV genotype 1 can be cured by standard of care, but nothing can be offered to the patients who are unable to eradicate infection on treatment."

For the study, Pawlotsky's team randomly assigned 334 patients with HCV to one of four treatment combinations of telaprevir, peginterferon and ribavirin

The results show that, by using a triple combination of telaprevir, pegylated interferon and ribavirin for 12 weeks, followed by 12 weeks of pegylated interferon and ribavirin, a sustained viral eradication can be achieved in 69 percent of cases, whereas only 46 percent of patients receiving standard of care for 48 weeks achieve a cure, Pawlotsky said.

"This is a breakthrough in HCV therapy," Pawlotsky said. "For the very first time, almost 70 percent cure rates are reached."

These findings open the way to an ongoing phase 3 trial, which could lead to the approval of this combination within the next two years, he said. "The triple combination could become the new standard of care," he noted.

In the second study, Dr. John G. McHutchison, a hepatologist and researcher at Duke University Medical Center, and his colleagues randomly assigned 250 HCV patients to standard treatment or combination therapy with telaprevir, pegylated interferon and ribavirin.

"We managed to cure significantly more patients by adding telaprevir to standard care," McHutchison said. "We cured 50 percent more patients, and we also reduced the duration of treatment from 48 weeks to 24 weeks."

Among patients taking all three drugs, 67 percent were cured compared with 41 percent of patients receiving standard treatment, the Duke researchers found.

McHutchison noted that side effects of pegylated interferon and ribavirin can include flu-like symptoms, depression, fatigue, insomnia and anemia, but adding telaprevir significantly reduces exposure to these drugs, which in turn makes the treatment easier to complete. Twenty-one percent of patients receiving telaprevir did drop out, with rash being the most common reason why.

In addition, 7 percent of the patients developed resistance to telaprevir. "There is an upside and a downside," McHutchison said. "The treatment's shorter, we cure more people, but unfortunately, there are more people who are discontinuing."

There is a phase 3 trial under way, McHutchison said. "If all goes well, this combination could be available in 2011," he said.

"The future looks very bright for people with HCV. Instead of being able to cure less than half of them, we can now, hopefully when these drugs are approved, say to any patient with genotype 1 hepatitis C, we've got a two-out-of-three chance of curing them," McHutchison said.

Dr. Eugene Schiff, chief of the division of hepatology at the University of Miami School of Medicine, thinks these studies are the first step in a major change in HCV treatment.

"Telaprevir represents the type of antiviral therapy for hepatitis C we will see in the future," Schiff said. "In the future, what you are going to see is a mixture of antivirals and my own prediction is you won't see it with interferon and ribavirin," he said.

Schiff thinks these new medications will get more people to go for treatment, because there are fewer side effects and the treatment time is shorter.

In the United States, about 4 million people have HCV, Schiff said. "Most of those people haven't been diagnosed. Of the 1 million who have been diagnosed, maybe 400,000 to 500,000 have been treated, and about 50 percent have been cured," he said.

"If you have an all-oral, highly efficacious regimen with relatively few side effects, then these people who haven't been diagnosed but know they have risk factors are going to come forward, because when they are diagnosed, there is going to be treatment that has a high percentage of cure," Schiff said.

Around the world, 180 million people have HCV. HCV is the leading cause of cirrhosis and liver cancer, and the most common reason for liver transplantation in the United States. HCV is spread mostly by sharing needles.